Configure the default route
Problem: Configure the interface IP address and realize the interconnection of the whole network through static route and default route configuration. 
1 Configure router AR1
Port 0, IP address is configured as 192.168.1.1, port 1, IP address is configured as 192.168.2.1
The router is configured as the default route, and the next hop IP is 192.168.2.2
2 Configure router AR3
Port 0, IP address Configured as 192.168.3.1, port 1, IP address configured as 192.168.4.1
The router is configured as the default route, and the next hop IP is 192.168.3.2
3 Configure router AR2
Port 0, IP address configured as 192.168.2.2, , Port 1, the IP address is configured as 192.168.3.2
The router is configured as a static route, add the 192.168.1.0 network segment, the next hop IP192.168.2.1, add the 192.168.4.0 network segment, and the next hop IP192.168.3. 1
4 of the test PC Connectivity between
can be pinged
